Soils and food sufficiency. A review

R. Lal

The Carbon Management and Sequestration Center, The Ohio State University Colombus, OH 43210, USA

Published online: 8 October 2008

Abstract - Soil degradation, caused by land misuse and soil mismanagement, has plagued
humanity since the dawn of settled agriculture. Many once thriving
civilizations collapsed due to erosion, salinization, nutrient depletion and
other soil degradation processes. The Green Revolution of the 1960s and
1970s, that saved hundreds of millions from starvation in Asia and
elsewhere, by-passed Sub-Saharan Africa. This remains the only region in the
world where the number of hungry and food-insecure populations will still be
on the increase even by 2020. The serious technological and political
challenges are being exacerbated by the rising energy costs. Resource-poor
and small-size land-holders can neither afford the expensive input nor are
they sure of their effectiveness because of degraded soils and the harsh,
changing climate. Consequently, crop yields are adversely impacted by
accelerated erosion, and depletion of soil organic matter (SOM) and
nutrients because of the extractive farming practices. Low crop yields,
despite growing improved varieties, are due to the severe soil degradation,
especially the low SOM reserves and poor soil structure that aggravate
drought stress. Components of recommended technology include: no-till;
residue mulch and cover crops; integrated nutrient management; and biochar
used in conjunction with improved crops (genetically modified,
biotechnology) and cropping systems, and energy plantation for biofuel
production. However, its low acceptance, e.g. for no-till farming, is due to
a range of biophysical, social and economic factors. Competing uses of crop
residues for other needs is among numerous factors limiting the adoption of
no-till farming. Creating another income stream for resource-poor farmers,
through payments for ecosystem services, e.g., C sequestration in
terrestrial ecosystems, is an important strategy for promoting the adoption
of recommended technologies. Adoption of improved soil management practices
is essential to adapt to the changing climate, and meeting the needs of
growing populations for food, fodder, fuel and fabrics. Soil restoration and
sustainable management are essential to achieving food security, and global
peace and stability.